Saturday, 30 April 2016

Water sheeting / Marangoni Effect - [: since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low surface tension, the presence of a gradient in surface tension will naturally cause the liquid to flow away from regions of low surface tension]

This is my preferred method of drying a vehicle paint surface; on the final rinse of the washing process remove the nozzle from the hose, reduce the water pressure and hold the end of the hose parallel to the paint and reasonably close as this is will prevent splashing as you flood the surface; this drying method helps to eliminate water-spotting. Use a forced air blower to remove water residue and then follow up with a waffle weave micro fibre towel to thoroughly dry the paint surface

I have tried many products over the years for drying but I finally found what really works the best, a micro fibre waffle weave drying towel. When they are wet they’re very soft and super absorbent, and glide easily over the surface, the ‘pockets’ in the weave ‘hold’ any dirt or surface debris unlike some other super absorbing products that trap dirt between the towel and paint surface with the potential to cause so serious scratches (never use it when it’s dry and stiff – it can potentially scratch) Wet –Wring- Wipe

That goes for whatever you use for drying, including waffle weave micro fibre towels. Ensure that the towel is really wet and then wring it out thoroughly before using. Blot as much water as you can, do not rub with the damp waffle weave towel. This gets rid of all the remaining drops and leaves only a little moisture behind. One wipe with the waffle weave in your other hand will result in a perfectly dry paint surface, using only waffle weave micro fibre towels with only one pass per area.

Waffle Weave Towel - a waffle (Piqué) weave towel is a synthetic micro fibre woven with a dimpled pattern, which much like an open-cell sponge provides thousands of small pockets to trap dirt or grit. The absorbency of these towels is quite remarkable; they are able to hold seven or eight times their weight in water. Instead of wiping with your waffle weave towel drying towel, blot the paint to minimize adding imperfections

Drying methodology- provided the paint finish has been rinsed adequately (See Drying a Vehicle ‘sheeting’ water) there should be no dirt residue. Water is a good solvent but a very poor surface lubricator. Try using a drying aid type detailer like Dodo Juice USA Time to Dry diluted 1:1 with distilled water, which provides lubricity to the paint's surface, in tandem with a damp waffle weave towel (wet, wring and then wipe) when drying your car - this will help break the surface tension of the beads causing the water to run off, allowing the towel to soak up more, and minimise water spots while lowering the friction of the towel over the surface.

Take two waffle-weave drying towels; one soaking wet (a wet towel wicks away more water than a dry towel) and one damp. Wring out the wet towel and use it as your primary drying towel, use this towel to blot- dry and check and rinse the towel often. Wring it out as you go, this will leave smaller wet streaks, which you can remove with your damp towel and it should leave a ‘streak’ free paint surface. This drying technique is excellent for black cars (including ‘soft’ single stage paint that shows every surface mark) but look so good when they are properly detailed.

This process never includes scrubbing, rubbing or applying any pressure whatsoever. The only time that pressure needs to be applied to a paint surface is when you are polishing.

A surfactant encapsulates any dirt and will provide lubricity to the paint's surface as you blot the paint to minimize adding imperfections. This method will safely remove any water spots that might occur

I would like to think that
these articles become an asset to anyone who is new to detailing and to
professional’s alike, as well as industry experts who seek to advance their
knowledge.

I hope the
above article was informative. By having some understanding of the ‘What’ and
‘Why’ as well as the ‘How’ along with a little science to help you understand
how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share
this article as it helps other detailers further their knowledge.

Friday, 29 April 2016

The
interior environment of an automobile can be extremely demanding on any
material used. Temperatures range from hot dry summer days, to freezing nights.
Both high and low humidity, even air conditioning that cools, but also dries.
Leather's greatest enemies are; sun, heat, body oils, perspiration (that
contains urea as well as organic salts and acids) and body heat, which causes
acids to become more aggressive and alters the viscosity of oils, allowing them
to permeate the leathers finish, and ultra violet radiation (UV), which dries
the hide, fades the colour by bleaching, and can cause the leather to fail by
drying out the fibres causing the urethane and / or the hide to crack.

Research

Correct
information regarding the care of leather is scarce, often contradictory,
misleading, or simply wrong. Misinformation can lead to inadvertent damage to
your vehicles leather upholstery; my goal is to present clear, concise,
accurate information.

There is a great deal of
conflicting information on leather care being put out by leather experts
themselves who recommend the same products and techniques be used regardless of
the grade or the finish applied or use baffling pseudo scientific techno speak
as another marketing ploy.

Furniture, Motorcycle, Equestrian Automobile
leather, all of which are have different type of leather finishes and require
different care. You do need to understand some of the basic chemistry behind
the tanning and be able to differentiate between the various finishes applied
to automotive leather in able to understand how to renovate, clean or care for
them, one size fits all is a vendor myth

All
of which makes it difficult to find a definitive, unbiased answer. Using the
correct product is important in order to protect your car’s interior. If you
keep your cars’ interior clean, you can easily save your car for a good couple
of years and it can stay in a ‘like-new’ condition, and maintain a better
re-sale value. Cleanliness is one of the major things buyers look for when
purchasing a vehicle.

There
are a few different types of leather and several types of finishes applied to
the leather used for vehicles upholstery. There are also a myriad of leather
care products available, which need to be used in accordance to the type of and
finish used in for your vehicles upholstery.

That
is why it is imperative, that if you are concerned about the results you wish
to achieve, you must perform a bit of research into finding the products
suitable for your requirements.

After
various meetings and discussions with leather tanners, their research and
development teams, chemists and fat liquoring formulators and many leather care
product manufacturers I’ve gained an understanding of this versatile material
on both a practical and scientific level.

It
had always confounded me that such a simple subject has been made into
something so complicated. I have always thought that the more facts and
information you have at hand the easier it is to judge what information you are
being given. After all, how can you fully understand and properly use any
product unless you have all the facts? In the final analysis; it’s your
vehicle, your hard earned money and your choice. (See
the article “Leather Upholstery Type Surface Identification”)

Materials Technology

Automotive OEM technology is
becoming more and more complex requiring educated and skilled technicians to
work on them. As the materials used are constantly changing we must maintain
our knowledge base and utilize the correct products and application
methodologies to keep up with emerging technologies.

Automobile
manufacturers have blurred the distinguishing lines on what exactly leather is.
There are many so-called ‘leathers’ that are actually the bottom split (the
fibrous part of the hide) which are covered with a vinyl or urethane coating.
Diagnosis is the key, not guess work. Before deciding on what products to use,
you need to ascertain the grade of leather and the type of leather finish
applied

Be cognizant that the leather and finishes used for
automotive upholstery varies from leather industry standard descriptions and
although the names are similar the type of leather, pigmentation and finish are
often very different. So it is very important to be
able to recognise the various finishes and materials used by OEM’s as they all
require different methodologies and products for proper care and maintenance.

Automobile
model ranges use different materials for their vehicles interiors; leather
upholstery like Aniline Immersion Dyed, Aniline Micro Pigmented, (Urethane)
Finished, Artificial leather such as MB-Tex and unfinished materials like
Synthetics and Alcantara, and sometimes combinations of products (Alcantara
seat inserts on leather seating) as well as various grades of leather hide,
full-grain, top-grain and split –grain (which is protected with urethane) all
of which require different products and applications methods.

Proper surface
care

Is
all about knowing the properties of the surface you want to treat and what
product contains the correct formulation of ingredients best suited for that
surface. Leather finishes are a very chemically complex material, and if the
product is incompatible with it in any way, it can exert a damaging effect:
finish peeling, finish cracking, color transfer ("crocking"), yellowing,
and general degradation are some of the problems that can be caused by the
application of an improperly formulated, incompatible leather treatment
product.

Micro Pigment (the correct name for Semi-aniline or Aniline used for automotive
leather) - is a term used by the leather industry to better describe leather
with a fine layer of pigment coating as opposed to the mislabelled ‘Semi Aniline’.
Aniline leather will absorb moisture unless it has been treated in some way.

King Ranch,
Chaparral or Castano (Ford F-Series) leather

Leathers
which have been both vat (immersion) dyed and have a finish on the surface are
referred to as Micro Pigment (automotive-grade
aniline) This type of leather has become more
popular in recent years because it incorporates much of the softness and feel
of fully aniline dyed leather with the protective benefits of surface finishing,
they are more susceptible to absorbing liquids because of the natural porosity
of the hide. Because they don't have a thick top coating the leather breathes
more easily and is cooler to sit on.

Early
model Ford F150 King Ranch leather upholstery used unfinished leather, which is
very susceptible to staining, discoloration, and you must be selective in
choosing the correct care products cleaner as the wrong products will give the
surface a greasy look to them.

Later
models switched to micro pigment (automotive-grade
aniline) finished leather. Thismicro pigment finished
leather is often protected by a micro-thin urethane, which is sometimes has pigmentation
(colour) added, hence the name. It is important to understand that the seats
were not intended to retain the pristine factory finish, they will weather and
gain character beginning almost immediately; they are also subject to photo
degeneration (fading) very quickly.

Remove
surface dirt and dust, cleaning the seams periodically is important as dirt /
grit will abrade the stitching causing them to fail, prise them apart, then use
a soft brush, vacuum and then use a foam cleaner, one section at a time, and
then finally wipe off with a clean, damp 100% cotton micro fibre towel

The
advantage of foam over liquid is the minimum amount of moisture, very important
for cleaning absorbent and moisture sensitive leathers.

Use foam cleaner, which should be given dwell
time and then gentle agitation with a medium stiff bristled brush to get the
product into the materials surface, the low moisture content of foam can then
be easily rinsed and the surface dried.
Remove excess product and debris with a clean, damp 100% cotton micro fibre
towel. If the foam is allowed to dry the soil will be re-deposited to the
surface. Check the results and repeat process as necessary

For
heavily soiled areas use a foam cleaner (Leather Master™
Foam Cleaner) that contains a surfactant that will
lift dirt and soil, allow react time to do its work and then use a soft brush
to agitate and loosen the dirt (Swissvax Leather Brush) especially on light coloured leathers; this enables the
cleaning of the micro pores and creases and lifts the dirt out and reveal any
further work that needs doing (dye transfer, stains, etc)

Spa cleaning
method

Soak
a micro fibre towel distilled water, wringing out excess and place in a
microwave oven. Proceed to wipe the leather to remove any dirt and moisten the
surface. Dependent upon soiling levels, a d-limonene (citrus) based cleaner (P21S
Total Auto Wash) added to the distilled water may
help release any oil / grease based soiling

Re-soften leather

If
you are working on a large item, do one section at a time so you can apply Leather Master™ Soft Touch
while the surface is still moist. This is not a
conditioner per se but is used to improve and maintain the tactile feel and lustre by rehydration and to
ensure the leather remains matte, soft and supple.

Apply
a small amount to a clean, damp 100% cotton micro fibre towel, use a circular
motion and slight pressure to ensure the product permeates the dried-out pores,
but do not push hard enough to damage the leather. Allow 20-30 minutes’ dwell
time and then wipe surface
with a dry 100% cotton micro fibre towel.

Protection

It’s
essential as it will protect the surface finish, without hindering
transpiration, while acting as a sacrificial layer; this way you are not
actually cleaning the Leather's original surface, but cleaning from the surface
of the protection. It also makes dirt easier to clean off

With
leather, it is much easier to practice prevention than it is to try to resolve
major challenges after the fact. Leather Protection will also work to remove
small surface scratches on Micro Pigment leathers. In general, Leather
Protection Cream is used as a final step in combination with most of the
Leather Master repair or touch-up products.

Leather
Master™ - Protection Cream (a Scotchgard™ type product specifically formulated for lather) the polymers
penetrate the surface of finished leather and cross-link to form a durable
protective film that is breathable, allowing transpiration and keeps the
leather supple. Being aqueous (water- based) it restores moisture to finished leather and
provides a protective sacrificial barrier against all
kinds of soiling, water, oil, alcohol-based stains and perspiration marks, so
you are cleaning the protective layer.

The Leather Protection Cream prevents
stains from absorbing deeply into the leather and becoming nearly impossible to
remove easily. It will not prevent finished leather hydration
(transpiration and evaporation of
moisture) as it’s water-based, although it coats the leather with a micro
fine coating; it will not seal it per se.

Leather
Master™ Scratch away - has been developed to erase
surface scratches and scuffs from semi-Aniline leather (King Ranch) it will
actually move colour on the surface of the leather in order to hide where the
colour is missing. It can be used on any colour of leather and is perfect for
dealing with fingernail type marks, light pet scratches and some delivery
scuffs. Pre-test on a hidden area but do not use if product darkens colour.

Leather
Upholstery Abrasion (Rub) Resistance Testing

The
abrasion resistance of finished leathers thin urethane covering is designed to
contend with clothing abrasion from exiting and entering the vehicle. Wear from
abrasion is a complex phenomenon and the information Taber Industries provides
at Abrasion Testing: Taber Industries-Material Test & Measurement is meant
to give you an introductory understanding of the common wear processes and
their underlying causes. Having this practical knowledge will help to address
the cost of failures caused by wear and abrasion.

Dirt
is the real enemy of leather, acts as an abrasive every time you sit down or
change your position while driving. Abrasion wear is due to hard particles or
hard protuberances forced against and moving along a solid surface.

These
hard particles might be commercial abrasives like silicon carbide and aluminium oxide, or naturally
occurring contaminates like dust particles and sand [crystalline silica
(quartz)]. If the abrasive particles are allowed to roll, rolling abrasion or
three-body abrasion occurs.

This
can lead to catastrophic wear, which is a rapidly occurring or accelerating
surface damage, deterioration, or change of shape caused by wear to such a
degree that the service life of a part is appreciably shortened or its function
is destroyed.

I would like to think that
these articles become an asset to anyone who is new to detailing and to
professional’s alike, as well as industry experts who seek to advance their
knowledge.

I hope the
above article was informative. By having some understanding of the ‘What’ and
‘Why’ as well as the ‘How’ along with a little science to help you understand
how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share
this article as it helps other detailers further their knowledge.

The less you physically
touch the paint surface the less likely you are to cause scratches. Most
surface scratches are caused by improper washing or drying, or by using
unsuitable media. Avoiding paint scratches (as
much as is possible) will lessen the need to use an abrasive polish along with
the subsequent loss of clear coat

Scratches in the clear coat or its
sub-surface, that is to say any form of damage that is in the top layer of the
paint surface, which includes; marring, swirl marks, scratches, stone chips,
water spots and acid etching. The most common form of sub-surface damage is
caused by road thrown stone chips, particularly on the front ends of cars.
Surface scratches are invariably caused by grit being trapped between the paint
surface and the applicator and being moved across the surface under pressure

Most scratches on a paint
surface are V or U shaped, being caused by a small sharp object (fine sand or
grit) and a slightly blunt object (belt buckle, button or zip) so an abrasive
polish and pad are more readily able to polish the sides and smooth the points
where the top of the scratch meets the surrounding paint's uppermost surface
(paint levelling).

What
makes a scratch visible is that it makes the paint surface two-dimensional and
the light reflects from the microscopic peaks and valleys differently from the
rest of the paint surface. When you abrade an area with a machine and foam pad
these abrasions form a uniform pattern (the machine /foam pad applies an even
and consistent pressure) and light reflects from its surface evenly without any
two-dimensional reflectance giving the impression that it’s been ‘removed’

The perfect, mirror-like
reflection of light from a surface, in which light from a single incoming
direction is reflected into a single outgoing direction the best example of spatial reflection is seen when
reflected from a flat level surface.

If the surface is perfectly
flat, light will be reflected to produce a mirror image of the surface. But if
there you have matte paint or are imperfections such as swirls, surface
contaminants, orange peel, or oxidation (dull, opaque or unlevelled paint)
light is refracted and the reflected light becomes distorted, diffuse reflection, which mutes the
shine.

Technically we have different types
of scratches because of the different ways they are introduced into the paint.

·Surface marring –could be in either in the paint surface or wax /sealant, theshallow surface marks often caused by
the incorrect use of a micro fibre towel, improper washing methodologies or the scratch pattern caused by a dual action polisher. Surface
marring is actually made up of tiny scratches, which can easily be remedied by
using a very light abrasive one-step polish

·Halo-scratches - (swirl marks or
spider webs) which, when the light reflects off the raised edges of the
scratches, appear to be circular but in reality they are made up of numerous
straight line random scratches which are caused by washing, drying and everyday
wear and tear. Some are surface marring, whereas others can be deep into the
clear coat.

·Holograms - (also called
buffer marks or buffer trails) which again are scratches but these scratches
are micro-fine patterned scratches which are caused by a high speed polisher
and an operator who doesn't know how to properly finish down their work. They
take on a 3D effect and if the car is moving or you move around the car they
seem to "flow" through the paint.

·Pig-tailing - caused by
dried compound residue lodged in the fibres of a wool pad

·Etching - is a type of paint defect that can vary in depth and frequency, but
creates a unique pattern dependant on how it is created. Etching is caused by
chemical reaction (Acid Rail, IFO, Bird excrement, bombs, and the residual
minerals found in water) on that paint’s surface that dissolves the surface,
creating depressions.

·Deep Scratches- a surface scratch that will `catch' your fingernail is
approximately 0.04 Mil (1.0 µ) deep will usually require wet sanding

·Haze - this is usually caused by using a pad / polish combination that
is too abrasive for the paint surface to finish without leaving very fine
scratch marks. Paint exhibits a general lack of gloss, this could also be
caused by harsh detergents, solvents, or hardly perceivable hairline scratches
or even a paint protection or polish that is not properly removed, all of which
leave behind a dull surface that doesn’t reflect light.

·Surface scouring –this is usually caused by abraded paint residue not the pad or
the polish used

·Swirl marks - Swirl
marks (buffer trails) ribbon-like abrasions, the things that cause swirl marks
are varied; an unnecessarily aggressive pad or abrasive, excessive speed or
pressure used or too stiff a backing plate are just some of the many reasons
for this type of surface defect. Even scratch-resistant and ceramic clear coats
are susceptible to swirl marks if polished incorrectly.

·Stone chips - and
other minor damage are not only aesthetically displeasing they look unsightly
and once they begin to accumulate, especially on dark coloured car. But worse
still, because the stone chips, scratches and scuffs have penetrated the clear
coat, your car will be prone to rust

Cause and Effect

Too ensure a near
perfect paint surface blemishes need to be removed. However, there are some
things to be cognizant of as it is possible to actually make things worse by
using improper methodologies.

Proceed with this
in mind; always choose the least intrusive product, it is preferable to polish
2-3 times to restore the paint film surface than to use an unnecessarily
abrasive machine polish / foam pad combination. Before commencing polishing do
a test panel on the car, once you have achieved the desired results with your
selected polish / pad combination then proceed to polish the rest of the panels

·Foam pad - using a foam pad that
is too aggressive or is not suitable for the polish selected

·Polish - select an abrasive
polish to match the scratch you are trying to remove; by using the least
abrasive combination of polish / pads to remove the defect, before moving up to
a more abrasive combination. It makes no sense to use a very aggressive polish,
that will remove most scratches but to the detriment of the clear coats
thickness. Know your product and its capabilities before using it.

·

Dirty pads - will become
more abrasive, as will pads that are simply sitting in a dirty or dusty
environment. Even microscopic dirt and dust on a pad can lead to swirl marks.

·Cross contamination- do not use
the same pad to apply differing products as cross contamination; i.e. a pad
that was used with a polishing compound may have traces left and if the same
pad is use for polishing it will cause scratches. However, if you thoroughly
clean pads right after use you shouldn’t have any problems with contamination
from different grades of polishes or compounds.

·Backing plate - a hard and
inflexible backing plate will affect the performance of a foam pad; by making
it slightly more aggressive (stiffness) and may cause swirl marks. The
inflexible plastic on many backing plates has zero give and therefore will not
adjust to the contoured body panels. The exception would be a plate bonded to a
thick layer of dense cellular foam.

·Speed - using too high a speed
will not necessarily get the job done faster as there is a risk of instilling
swirl marks or strikethrough, which will need to be corrected to remove

·Pressure - excessive pressurewill make the pad / polish
combination more aggressive, this has the effect of increasing kinetic energy
(friction heat) which may result in a strikethrough, a friction paint burn or
paint delamination from the substrate.
Increased surface friction will also cause swirl marks

·Heat - excessive heat and a combination of excessive pressure (surface resistance) speed
and an aggressive pad / polish combination will rapidly generate surface heat,
this will soften the paint and may cause delamination from the substrate,
surface hazing, strikethrough and greatly increase the chance of swirls.

·Pad angle – ideally a pad should
be operated flat to the surface; this provides the correct contact surface area
along with sufficient surface lubrication from the polish oils. By turning a
pad on an angle you reduce the surface are contact, increasing pressure and
reduce the amount of surface lubrication available. Incorrect polish techniques
will lead to swirl marks

·Insufficient product - without the polish
lubrication oils, dry buffing will cause delamination from the substrate,
surface hazing, strikethrough and greatly increase the chance of swirls.

Common causes of scratches

•Improper methodology / tools
used when washing or drying a paint surface. This is the most common cause of
surface scratching / marring) and accounts for as much as 75% + of surface
marring

•A large proportion of all
paintwork scratches are caused by automated car washes. Minute particles of
hard materials, such as road dust and sand, become lodged in the rotating
brushes and etch scratches into the paint surface. These “hair-line” scratches
are particularly noticeable in darker paint shades.

•Using an unsuitable
applicator or brush to clean the vehicle or remove snow etc.

•Using cheap micro fibre or
terry cloth towels or some wash sponges will scratch the paint as these
materials are hard and unforgiving, inflicting scratches without the need for
grit particles

•Visible damage-if the
scratches show a black, grey or white colour it probably means that it's
compromised the paint system through to the primer. They can usually be
rectified by thoroughly cleaning the affected area, then apply a rust
preventative primer before the application of both a colour and clear coat with
a solvent or a slightly abrasive pre-wax cleaner or polish. Re-apply a
protective polish and sealant after the repairs have been affected and the
paint has had time to cure.

•Visible abrasions- dragging
an object across the top of the trunk lid often cause this kind of surface
damage, or careless use of the car keys or even fingernails around the door
handles. They can usually be rectified with a slightly abrasive pre-wax cleaner
or an abrasive polish.

•Surface scratch (or marring-) most
probable cause is by automatic car wash or poor cleaning techniques. The
marring looks like thousands of tiny single directional uniform scratches that
cause light to refract instead of reflect, this kind of damage is usually
confined to the clear coat, and can usually be rectified with a pre-wax cleaner
or polish.

Deep Scratches

A surface scratch that will
`catch' your fingernail is approximately 1.0 µ (micron) deep will
usually require wet sanding and the clear coat refinishing Removing a scratch
requires removing the layer of paint that contains the defect; you need to
level the paint to the lowest point of the scratch.

Removing more than 0.3 mil (8µ) of clear coat
will cause premature paint film failure as UV protection percolates to the top
of the clear coat. Check paint film thickness with a Paint Thickness Meter
(PTG) before you attempt to remove

As you go over a deep scratch, the
abrasives round off the edges of the
high spots of the scratch. The result is a shallower scratch (when no full
correction can be made) rounded edges don’t reflect light the same way a sharp
edge will and is therefore less noticeable.

Unfortunately, a more and
more common form of deep scratch is those inflicted with a sharp object i.e. a
key. It may be necessary to carry out some localized wet sanding to facilitate
full removal of any deep scratches, once again, paint thickness must be
checked, and if the paint is too thin wet sanding should not be considered

Backlighting

Clear coated paints
show minor swirls and scratches more readily than pigmented paint (single
stage) due to an optical effect called backlighting. Light penetrates the clear
coat and is reflected from pigmented paint (colour coat) which in turn reflects
any imperfections in the surface of the clear coat, making them highly visible.
As you
drive towards the setting sun or oncoming headlights on a rainy night, every
speck of dirt, smudge or smear on your windshield is suddenly very obvious.
They are much more noticeable when sunlight or oncoming headlights back-light
them.

Removing surface scratches with a
machine

Removing a scratch requires
removing the layer of paint that contains the defect; you need to level the paint
to the lowest point of the scratch. The dual action of a random orbital motion
will require more applied pressure to work the compound into the scratch as
opposed to the singular action motion of a rotary spinning with less applied
pressure. Due partly to its indirect application of pressure; it removes more clear by putting an
uneven pressure on the abrasives

a)A
dual action polisher’s orbital’s operating action (throw or offset) is not as
efficient at transferring the energy required to create the kinetic friction
required, because it puts an uneven pressure on the abrasives. It spins on a
double axis, resulting in a pretty much "random" motion of a single
point on the pad. This simulates the "random" motion of hand
application of polishes.

The
downside of this is that you cannot abrade the clear coat either to remove
scratches. The PC pretty much just smoothes over the tops of the scratches, not
really sanding away any measurable clear coat. To remove scratches, you have to
make multiple applications to see a visible improvement. So for these reasons a
random orbital polisher removes more paint than a rotary circular polisher to
remove the same surface defect

b)With a high-speed rotary polisher - you will be removing a
certain amount of clear coat and actually levelling the surface. This is good
because you truly remove the scratches, not just making them less refractive to
light, as the PC does. The problem is that you only have about 1.5 or 2 mil of
clear coat to work with.

A
rotary polisher requires less pressure and its circular motion is a more
directly applied force is very efficient and will remove more paint for each
polishing step, which is usually 2-3 to remove surface defects. Its rotational
action is able to focus kinetic friction on the high spots the paint more
efficiently.

c) Using a moderate to light polish; and
utilizing a rotary polisher will remove approximately 0.000025 - inches (0.635
Microns) from the paint surface (they are many variables such as
polish/compound and speed / pressure used that may affect the paint removed)
You seriously have to make a judgment call about whether any defect is so
severe that you cannot live with it and therefore it is worth risking clear
coat failure to remove it with the rotary

d)Block or wet sanding (finishing paper and a sanding block) is
the most efficient process for paint scratch / defect removal. A polish or
compound applied by the sanding block with constant pressure applied to
maintain a flat even surface contact. Because of its linear process you abrade
the paint surface until the scratch or defects are removed.

Note

1.It is preferable to polish 2-3 times to restore the paint film
surface than to use an unnecessarily abrasive polish / foam combination

2.Wool pads are not recommended for random orbital machines
(Porter Cable 7424, etc.) as wool pads nap / fibres works more efficiently with
a centrifugal motion Foam cutting pads tend to be much’ stiffer’ than wool
fibres and thus will transfer the movement of the machine to the paint surface
more efficiently than a comparable wool pad on an orbital polisher

4.Always use the least aggressive product first, and then
evaluates the surface, then only if necessary `step-up' to a more abrasive
product and / or pad.

Levelling paint

When
a detailer uses the term "levelling paint" it really means that they
are going to be abrading the surrounding paint area that that contains the
defect (scratch, swirls, surface marring, etching, pitting, etc.) So they are
not ‘removing the imperfection’ just making the surrounding edges of the
scratch flat. It is possible to remove a scratch by using a high-speed rotary
and abrading the clear coat to a lower level then the base of the scratch,
which will remove clear coat, just be aware of how much clear coat you remove,
as you don’t want to compromise the paint systems protection.

Removing more than 0.3mil (8µ) of
clear coat will cause premature paint film failure as UV protection percolates
to the top of the clear coat, there is UV protection all the way through the
paint, but the majority of it rises to the top with the thinner solvents and
particles. As a point of reference a sheet of copy paper is 3.5Mil (89µ) a
surface scratch that will `catch' your fingernail is approximately 0.004 Mil
(0.01µ) deep will usually require wet sanding and refinishing.

Modern
clear coat paints are formulated from polyurethane, applied as a microscopically
thin ‘elastic’ film, 1.5 – 2.0 Mils, too much friction heat will cause it to
expand, driving the scratches deeper into the paint surface. Always be aware of
paint surface temperatures (localized paint temperature should be limited to
110.oF.

In accordance with the Society of Automotive
Engineers (SAE) study a temperature of 115.oF< will cause the paint to
soften), and thickness, i.e. how much of the surface are you removing (See also
Paint Thickness Gauge)

Light Surface Marring

The light surface
marring that result from wiping down with a towel or the scratch pattern caused
by a dual action polisher Surface marring is actually made up of tiny
scratches, which can easily be remedied by using a very light abrasive one-step
polish (Menzerna PO 203 S - Power
Finish) and a protective wax
and/or polymer sealant. This way you’ll maintain the original paint’s integrity
for decades, with allowance only for environmental erosion.

Methodology

1.Wash the paint surface

2.Bonded contaminants on the cars paintwork should be removed
using a detailer’s clay bar to leave a smooth surface ready for machine
compound or polish.

3.Throughout all stages of the polishing process the cars trim
adjacent to the area being worked on should be carefully protected using
painters tape to mask it to avoid damage.Protect sunroof seal, headlight covers, lighting rubber seals,
windscreen surround, pant edges, vehicle emblems and model identification
numbers, etc.

4.Whenever you’re removing painter’s tape from automotive paint,
always pull back on the tape at an angle as a safety precaution.

5.Start the polishing process with a diagnosis of the paint finish
and then proceed with the least aggressive polish / pad combination on a ‘test
section’ panel, once you have established a suitable polish/pad combination
proceed to polish / refine the paint surface

6.It may be necessary to carry out some localized wet sanding to
facilitate full removal of any deep scratches, once again, paint thickness will
be checked, and if the paint is too thin wet sanding should not be considered.

7.Finally use a polish to remove any surface imperfection and then
a fine polish / pad to burnish the paint surface

8.Carry out a wipe down process to ensure all oils and surface
defects have been removed.

9.Re-wash to remove any polishing dust and / or debris

10.The final step could be to use a glaze, pre-wax cleaner or go
right to protecting your paint with a sealant and/or wax.

Always be willing to learn; because the more you learn,
the more you’ll realize what you don’t know.

It is said that knowledge is power, with the caveat
that it includes access to a reliable information sources. I would like to
think that these articles become an asset to anyone who is new to detailing and
to professional’s alike, as well as industry experts who seek to advance their
knowledge.

I hope the article are informative. By having some
understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little
science to help you understand how the chemicals we use react, you can achieve
the results you desire.

I would appreciate it if you would share these
articles as it helps other detailers further their knowledge.

As always if you have questions, I’ll do my best to
answer; bear in mind the only stupid questions is the one that was unasked.
Questions and/ or constructive comments are always appreciated.

About Me

These articles are college level PhD(tailing) material that is and a wealth of factual discussion that is easily understood and very informative. It is available on Amazon’s Digital Text Platform, Kindle 3 and the Apple iPad. The information in these articles is factual rather than subjective. It is not intended to be a source of opinion but rather knowledge attained by verifiable means, based on tried and proven techniques, methodologies and facts about detailing and the chemicals and products used
My garage
Jaguar XFR V8 Stratus Grey
‘10, Audi S8 4.2 Night Blue Pearl
'08, Mercedes 380SL '84 Beige